This invention relates to a surgical instrument to be used by a surgeon to sever living tissue and, more particularly, to cut openings of a predetermined size in the tissue such as vessels or the like.
The present invention is directed to cutting of living tissue to form openings therein of a predetermined size and is particularly useful for cutting openings in tubular anatomical vessels, such as blood vessels, ureter, vas deferens, fallopian tubes and biological sheathes for nerve bundles and will be described hereinafter in connection with the preferred use which is as in arteriotomical instrument for cutting holes into blood vesesls to which will be attached another donor vessel by an anastomosis technique. Typically, in an arteriotomical procedure, the surgeon will locate the area which the anastomosis is to be made and with a first instrument, such as a forceps, or a curved surgical needle lift, and pull a portion of the recipient vessel outwardly and then use his other hand with a scalpel or a scissors to cut about the lifted portion to form the opening in the vessel. The size of the opening should match the outer diameter of the donor vessel and the opening size is estimated by the surgeon based on his experience. In many instances, as in microsurgery, the donor vessel may be very small, e.g. about one, two or three millimeters in diameter. For best results, the size of the opening should be such that the new donor vessel be stretched slightly and certainly not compressed in size, when secured to the recipient vessel, to prevent a reduction in size of donor vessel lumen. Thrombosis at the anastomosis site may occur if the vessel lumen is constricted and blood flow is obstructed thereby. If the cut opening is made too large, then it is difficult to connect the new vessel to the first vessel without leakage at the sutured connection between the vessels.
Additionally, it is often difficult for the surgeon because of the space limitation of the surrounding tissue and other living material to be able to manipulate the scalpel or scissors to obtain a good, uniform, circular cut to form the opening in the vessel. Often the surgeon is located on one side of the vessel, used called the control side, and has difficulty in making a true semi-circular cut on the opposite obscured or non-control side. Also, the opening being cut by the surgeon in conventional techniques is adversely affected by having a thicker vessel wall than anticipated because of the accumulation of arteriosclerotic material on the intima of the vessel. More specifically, the surgeon gauges his cut on the exterior of the blood vessel and his incision is at an inclined angle such that the thicker the wall the smaller will be the opening into the lumen. Thus, where the vessel wall has substantial increase in wall thickness due to arteriosclerotic material accumulation, the interior opening will be smaller than anticipated. With the present invention, however, the thickness of the wall does not adversely affect the size of the hole at the interior of the vessel because the cut is sized from the interior of the vessel wall. Also, with the present invention, the cut is made automatically and is made generally circular and gauge means are provided on the instrument. Thus, the surgeon is provided with an indication of the size of opening that will be cut with the instrument so that the surgeon may match more accurately the opening size to the donor vessel size and the surgeon may obtain uniform and consistent sizes of openings.
Further, the instrument is easy to use and may save surgical time which is very important in situations where the anastomosis is desired to be done as quickly as possible to allow resumption of blood flow as soon as possible.
Accordingly, a general object of the invention is to provide a new and improved surgical instrument for cutting openings in living tissue.
A more specific object of the invention is to provide a new and improved arteriotomical instrument for cutting openings in blood vessels.
These and other objects and advantages of the invention will become apparent from the following detailed description and accompanied drawings in which